    <ul>
        <li><a href="" ><img src="img/bottom_home.png" id="bottom_home"> <br> <span>首页</span> </a></li>
        <li><a href="" id="bottom_order"><img src="img/bottom_order.png"> <br><span>排行 </span> </a></li>
        <li><a href="" id="bottom_signup"><img src="img/bottom_signup.png"> <br><span>报名</span> </a></li>
        <li><a href="" id="bottom_prize"><img src="img/bottom_prize.png"><br><span>操作指南</span> </a></li>
    </ul>
